Rotary offset printing machine



July 28, 1931 w, R SS ER 1,816,796

ROTARY OFFSET PRINTING MACHINE Filed Oct. 13, 1950 I n var/for:

Patented July 28, 1931 UNITED STATES PATENT OFFICE WALTER R6SS GEB, OF HEIDENAU-SUD, GERMANY, ASSIGNOR TO THE FIRM ROCK- STBOH-WEBKE AKTIENGESELLSCHAFT, F HEIDENAU, GERMANY ROTARY OFFSET PRINTING MACHINE Application filed October 13, 1980, Serial No For adjusting the pressure of the cylinders in rotary offset printing machines having a rubber covered oifset cylinder, the necessary means are employed for applying and taking 01f the pressure. Such means comprise eccentric bearing bushes in which the shafts connecting rods arranged so as to-be adjust- Figure 2 a plan partly in section.

able in length. By this means a variation in the length of the connecting rods results in a greater or less pressure being applied between the cylinders. When the connecting rods are adjusted there is the danger however that the length of the rods on both sides of the machine will not be adjusted so as to be exactly the same and that by this means the pressure between the two cylinders will be greater on the one side than on the other. Moreover, canting of the gudgeons will take place, and further it is only with great difiiculty, if it is not altogether impossible, that the pressure can be adjusted during the operation of the machine.

The invention removes these drawbacks in that the axis, about which the levers oscillate which serve for transmitting the pressure adjustment, is subjected to a displacement such that the intensity of pressure can be adjusted to any desired degree without any lack of uniformity in the intensity of pressure between the cylinders being able to set in and without the application and the relief of the pressure being thereby affected in the least degree.

The invention is-illustrated byway of enample in the accompanying drawings, in which 'Figure 1 shows the improved apparatus in elevation, and

. 488,447, and in Germany January 16, 1930.

Referring to the drawings, the rubber cylinder a. is non-adjustably journalled in concentric bearings in the side parts of the machine frame, while the impression cylinder I) can be displaced in position by means of the eccentric bearings 0' by rotating the latter.

A shaft (Z having eccentric gudgeons which are journalled in the side parts of the printing machine can be turned by means of a handle a and fixed in position by means of the locking member f on the screw-bolt g, the wedge h, and the guide-piece 11. On the inside part of the shaft (l is rotatably jour'nallod a hollow shaft is .which is rigidly connected to a double-armed lever Z and a single-armed lever m. The eyes a of the two levers Z and 'm are movably connected by means of the connecting rods 0 to the lever arms of the eccentric cylinder bearings c. lVith the eye p of the double lever Z engages a connecting rod 1, to which, by known means, a to-and-fro. alternating movement is imparted. This to-and-fro alternating move ment is transmitted by means of the machine parts above described, the eccentric cylinder bearings, which, owing to their rotation, move the impression cylinder 19 away from the rubber cylinder (1 or press it against the latter.

If new the shaft cl is turned out of its mid-- dle position v(Fig. l) by means of the lever e, then the centre of the hollow shaft will be displaced from the point 1 to the point 2, or the point 3.

As the point p of the double-armed lever Z is held fast by the connecting rod 1', then the rotation of the shaft d will result in a corre-' 'sponding rotation of the eyes it of the levers m and Z from the point 4. to the point 5 or the point 6, and thereby a rotation of the eccentric bearings 0 of the impression cylinder, whereby the pressure is adjusted.

What I claim is 2-- 1. Apparatus for adjusting the impression pressure in rotary offset printing machines, comprising the combination with a machine frame, an offset cylinder, an impression cylinder, eccentric bearings for one of said cylinders rotatable in said machine frame and bearings for the other cylinder in the said frame, of oscillatable levers operatively 'connected to said eccentric bearings and displaceable supporting means for said oscillatable levers mounted in the frame, said levers being rotatable on said supporting means, as and for the purposes set forth.

2. Apparatus for adjusting the impression pressure in rotary offset printing machines, comprising the combination with a machine frame, an offset cylinder, an impression cylinder, eccentric bearings for one of said cylinders rotatable in said machine frame and bearings for the other cylinder in the said frame of a shaft havin eccentric ud eons 7 D b b j ournalled in the frame of the machine, levers oscillatably mounted on said shaft and operatively connected to said eccentric bearings and means connected to said levers for rocking them, as and-for the purposes set forth.

3. Apparatus for adjusting the impression pressure in rotary offset printing machines, (-on'lprising the combination with a machine fran 1e, an offset cylinder, an impression cylinder, eccentric bearings for one of said cyl-' inders rotatable in said machine frame and bearings for the other cylinder in the said frame, ofa shaft having eccentric gudgeons journalled in the frame of the machine, a hollow shaftrotatable on said shaft, levers fixed to said hollow shaft and operatively connected to said eccentric bearings, means connected to said shaft having eccentric gudgeons for rotating theshaft and for securing the shaft in adjusted position and means 0011- nected to'said hollow shaft for rocking the hollow shaft, as and for the purposes set forth.

Intestimony whereof I have signed my name to this specification.

WALTER RossGER. 

